The invention relates to a method for making veneer with natural veining, the so produced veneer and a machine for carrying out the method, in which the veneer is made from a timber tooled previously to have a substantially cylindrical form and has a central longitudinal axis, and an open end comprising the steps of rotating the timber around its axis with a predetermined speed; using a knife that has a cutting edge to contact the timber close to the surface, and separates the veneer from the timber by cutting.

US 2007/0074787 A1 discloses a method of cutting a wood block for production of veneer by a rotary veneer lathe. The veneer lathe includes a veneer knife, a number of rotatable peripheral drive wheels placed parallel to the veneer knife and each having a number of tooth-like projections pierceable into a wood block for driving the wood block for rotation about its axis, and a guide member for guiding veneer peeled from the wood block. In this method the cutting or shelling takes place parallel to the axis of rotation.

In several occasions the designer who has the task of finding high quality utilization of veneer has the intention to place a veneer on an object where the natural pattern, also called veining of the wood is arranged symmetrical to an imaginary central line. With the mentioned conventional parallel shelling the patterns obtained during a single revolution of the lathe appear side-by-side and not in a symmetrical relationship. To satisfy the objective of making a symmetrical pattern can be realized if two patterned halves are cut out from the veneer and one half is reversed then the two cut haves are arranged side- by-side. This operation is time consuming and the preparation of the final decoration from two pieces will always remain noticeable.

There is a further problem, namely the mentioned parallel shelling requires timbers of large size that have great weight, and the machinery must be made large, heavy and robust.

On the other hand, there are certain types of trees which can or should be cut after having reached a certain age and size wherein their trunk has a smaller diameter, falling typically in the range of 70 to 250 mm or slightly above, and with conventional veneer manufacturing technology timbers made from such trees cannot be used in an efficient way for producing veneer. The object of the invention is to suggest a new technology of shelling a timber, in which the veneer takes a substantially circular or ring-like form which comprises a predetermined number of similar patterns arranged angularly offset from each other, wherein the method can efficiently utilize timbers with diameter under about BOO mm.

To achieve this objective a method has been provided for making veneer from a timber tooled previously to have a substantially cylindrical form and having a central longitudinal axis, and an open end, the method comprises the steps of rotating the timber around its axis with a predetermined speed; using a knife that has a cutting edge to contact the timber close to the surface, and separates the veneer from the timber by cutting, wherein according to the invention the method comprises the steps of adjusting the edge of the knife so as to close an acute angle which is between about 15° and 5° and positioning the knife so that a first end of its edge lies close to the axis and the second end lies at least at the outer diameter of the timber, moving the knife and the timber against each other in axial direction so that the edge of the knife contacts first the outer diameter of the timber and providing gradually a conical mantle surface for the timber, and adjusting said axial movement to provide a continuous veneer by the cutting edge, and guiding the peeled veneer to take a continuous surface at least through a prede termined number of revolutions of the timber.

It is preferred if the edge of the knife closes a small cutting angle with the tangential plane of said conical mantle surface, the cutting angle is defined by the hardness and structure and diameter of the timber and the shape of the edge.

The realization is easier if the diameter of the timber is at most 200 mm, the angle is around 9,4° and the knife has a length of about 600 mm.

In preferred embodiments during the axial movement the knife is stationary and the timber is moved towards the knife, or the timber is stationary and the knife is moved towards the timber.

It is preferred if the diameter of the timber is between 70 and 250 mm.

According to the invention a peeled veneer is provided that comprises at least one full circle or ring of veneer material consisting of a plurality of repeated patterns, wherein each pattern corresponds to a full revolution of shelling of the same timber along a conical cutting path.

In a preferred embodiment the number of patterns is 6. In a further embodiment the full circles form a spiral.

According to the invention a shelling machine has been provided for producing veneer from a timber that can be used for carrying out the method, wherein the machine has an elongated body, a conical cavity defined in the body and having an axis, a straight gap is provided in a wall of the body, said wall has a plane parallel to a tangential plane of the conical cavity, the gap extends both in parallel with that plane and with the axis of the conical cavity, a knife is attached to a side of the gap with an edge lying in the plane of said wall and extending substantially through the length of the gap and slightly inserted into the gap, the insertion defines the thickness of the veneer to be provided, the conical cavity has a mouth opening greater than the diameter of the timber, and the machine comprises means for rotating the timber around the axis and means for inserting and axially moving the rotating timber into the conical cavity.

In a preferred embodiment wherein the knife is fastened to the body by a plurality of spaced bolts.

In a further embodiment the body has a lower part with a bottom piece and two support surfaces all have lower surfaces parallel to the axis, and the machine comprises a base with respective spaced recesses also extending parallel to the axis, and the body is positioned on the base by means of intermediate support members placed on rails inserted in said spaced recesses.

The invention will now be described in connection with preferable embodiments thereof, wherein reference will be made to the accompanying drawing. In the drawing:

Fig. 1 is a schematic side view of a prior art lathe used for timber shelling;

Fig. 2 is the schematic elevation view of the machine shown in Fig. 1;

Fig. 3 is the perspective view of an enlarged detail how veneer is made and rolled by the machine shown in the previous figures;

Fig. 4 shows two veneer pieces beside each other, one reversed by 180°;

Fig. 5 shows the juxtaposition of the cut pieces shown in Fig. 4;

Fig, 6 is a schematic illustration of the shelling according to the invention with a piece of veneer created;

Fig. 7 is an enlarged detail of Fig. 6 without the veneer;

Fig. 8 is the top view of a veneer made by the method according to the invention;

Fig. 9 is similar to Fig. 8 illustrating three different rectangular cuts; Figs. 10 to 12 sow the three rectangular pieces after being cut, in enlarged view;

Fig. IB shows the schematic perspective view of a shelling machine with the veneer made;

Fig. 14 shows only the machine of Fig. 13; Fig. 15 is an exploded view showing the main parts of the machine of Fig. 14; and

Fig. 16 is an illustration how the timber 1 can be rotated.

In Figs. 1 to 3 a conventional veneer producing method is illustrated with a lathe 2 used for the method. A timber 1 with appropriate length is placed on the lathe 2 (following an initial preparation), wherein the timber 1 is turned around its central axis 3 which falls in the axis of the lathe 2. A knife 4 touches the outer portion of the timber 1 in a slight depth and closing a small angle with the tangent plane of the timber. The edge of the knife 4 is parallel to the axis of rotation, whereby the knife 4, when adjusted properly, cuts and prepares a continuous sheet of veneer 5 that can be wound to form a cylindrical roll 6. The thickness of the veneer 5 corresponds to the depth of the knife from the outer surface of the timber. As the process continues, the knife 4 is moved normal to the axis 3 to follow the slowly decreasing diameter of the timber 1 and to preserve the same thickness of the veneer 5. This method can be called as peeling or shelling, since the useful material is the veneer 5 prepared in this way. After each revolution of the axis 3 the same natural veining of the timber 1 appears as a repeated side-by-side pattern. In certain fields of application using veneer, mirror symmetry of the veining on the piece covered by the veneer is required. In Fig. 4 sketch a shows a veining pattern obtained on a veneer sheet 11 made during a full revolution of the timber. During the next full revolution the same veining pattern is obtained on veneer sheet 12. In order to create mirror symmetry, the second veneer sheet 12 was turned or reversed by 180 ° as shown in Fig. 4, sketch b when the two sheets 11 and 12 are arranged beside each other. In case an exemplary application requires a rectangular piece 13 (drawn by dashed line in Fig. 4) with a pattern showing mirror symmetry, the piece 13 should be made by cutting half of the piece 13 from the first sheet 11 and the other half from the turned second sheet 12. Fig. 5 shows that these cut halves are united at a centre line 14 drawn with a dashed line to obtain the required piece 13 with mirror symmetrical pattern. This is a rather expensive way of making the piece 13 as the second sheet 12 has to be turned and the rear surface will become its front surface, and the cutting and fitting the two halves requires excess work and time.

The method according to the invention produces juxtaposed veneer elements which together make a closed, more or less circular or ring-like sheet that comprises a predetermined number of repeated patterns which are naturally arranged in different angular positions beside each other.

Reference is made now to Figs. 6 and 7. The shelling uses again circularly tooled timber 1 as starting material. At this time cutting edge 16 of knife 15 of the machine shown in Fig. 6 is symbolized by a dashed line because it is covered. This edge 16 closes an acute angle with the axis of rotation 3. Fig. 7 is an enlarged detail, in which the knife and a portion of its edge 16 can be observed. Because of this obliquely arranged knife 15 and edge 16 the shelling is similar how conventional pencil sharpeners look like. In Fig. 6 the peeled veneer 10 can be seen with the veining or pattern formed. The edge is not only inclined relative to the axis, but also has a cutting angle defined in the direction of the rotation and an insertion depth that defined together the thickness of the veneer and the perfect cutting the takes place without tearing. In this respect (what concerns the design of the cutting edge) the shelling according to the invention does not differ from how veneer is cut in conventional methods. Similarly, the thicknes of the enee can be the same as of conventional veneers, being smaller than 1 mm and typically falling in the range of 0.3 to 0.8 mm. This range is in no way limiting and depends of the type of the wood and on the required application of the veneer.

There are certain repeated patterns 17a, 17b, 17c angularly displaced from each other. Each of them corresponds to a full revolution of the timber 1. In Fig. 6 the peeled veneer 10 looks like in a distorted view, and the actual shape of a piece of veneer 10 is shown in Fig. 8. In this example the circular piece of veneer 10 is obtained after six full revolutions of the timber 1, and there are six repeated patterns 17a, 17b, 17c, 17d, 17e and 17f. The number of repeated patterns depends on the angle that the edge 16 of the knife 15 closes with the axis 3, but the use of angles is preferred in which the circular shape of the peeled veneer pieces 10 corresponds to a full number of turns i.e. it comprises fully repeating patterns or veining. The number of pattern is therefore is an integer number. Reference is made now to Fig. 9 which is the same as Fig. 8 but here we have drawn different rectangular pieces 18a, 18b and 18c on the veneer 10 which should be cut out for satisfying the need of different customers. The rectangular piece 18a is chosen without symmetry, but the other rectangular pieces 18b and 18c comprise mirror symmetrical patterns and to obtain them there was no need to cut and fit together two half pieces and to reverse one of them as it was shown earlier because this specific shelling of the timber resulted in the repeated patterns 17 arranged in respective angularly offset positions, wherein the adjacent patterns (when cut parallel to the tangent line of the circular outer shape) will stand in mirror symmetry with respect to each other. A further specific property of this kind of shelling lies in that each of the repeated patterns 17 correspond to the cross section of the timber in a distorted scale defined by the cutting angle. Such patterns have a rather pleasing appearance ready for use in several applications.

Reference is made now to figures 10 to 12 which show the respective rectangular pieces 18a, b and c in enlarged view. Depending on the place of the cuts very interesting and aesthetically pleasing patterns are obtained in which the veining of the veneer has dominance, and in case of the pieces 18b and 18c the mirror symmetry is automatically provided. Such pieces can be further processed by known technologies for making high quality surface decorations. In figures 13 and 14 an appropriate embodiment of a timber shelling machine 20 is shown, wherein Fig. 14 shows the perspective view of the shelling machine 20 and Fig. 13 is a sketch illustrating the tooling of the timber 1 and showing the peeled veneer 10 as collected in a conical roll 6. The machine 20 has a substantially oblong body 24 in which a conical cavity 21 is formed, wherein the cone's angle is the double of the angle a of the inclination of the knife by which the timber 1 is shelled. The body 24 has a top wall 19 which is inclined so that the plane of the top wall 19 is parallel to the outermost tangential plane of the conical cavity 21. There is a linear gap 22 extending along the central part of the top wall 19 in parallel to the axis of the timber 1 inserted in the conical cavity 21. The top wall 19 walls that define the sides of the gap 22 can be formed as wedges that narrow down towards the gap 22. On the top wall 19 at one side of the gap

22 which is opposite to the direction of rotation of the timber a plurality of knives 23a, b, c and d are arranged and fixed with respective edges projecting into the gap 22 according to the intended thickness of the veneer. The shelling machine 20 looks like an enlarged pencil sharpener, and its operation is also similar to it.

In Fig. IB the veneer 10 can be seen as discharged from the machine 20. Of course, this is an illustration only, because in the actual realization the veneer is guided and supported by an appropriate curved support plate (not shown) immediately after leaving the region of the knife.

Reference is made now to Fig. 15 that shows the exploded view of the main parts of the shelling machine 20. It can be seen that the top wall 19 closes an angle 2a with the bottom of the body 24, wherein a is the angle that the edge of the knife 23 closes with the axis of the conical cavity 22 (see the illustration on Fig. 16).

The body 24 has a beam like central bottom piece 25 that serves as a reinforcement member and two horizontal support surfaces 26, 27 with elevated planes that receive guiding and holding members 28, 29 and 30, 31 at either side fixed under them. In one side upright fixing bolts are also shown by which the members 28 - 31 can be fixed to the bottom of the body 24. The number of the holding members 28 - 31 depends on the length of the machine that can be in the range between about 0.8 and 2 m but this range is not limiting. The bottom of each holding members 28-31 has a special hollow profile that fits to profile of a respective rail 32, 33 extending in straight line in axial direction.

Under the members 28-31 and the rails 32, 33 a flat base 34 is shown which holds the machine 20. On the top of the base 34 a pair of straight spaced recesses 35, 36 is formed for receiving and holding the rails 32, 33.

On the top wall 19 of the body 24 at one side threaded bores 37 are formed for receiving respective threaded bolts 38 that have the task of fixing the knife 23 at several discrete places. The knife 23 has respective cuts for receiving the bolts 38. The length of the knife 23 is defined by the diameter of the timber 1 and the angle a. In case of an angle of 9,4° and a diameter of 200 mm the length of the knife 23 should be 600 mm.

The exploded sketch of these parts shown in Fig, 15 is a simple illustration only, because the actual design might be different, however, it is important that the position, angle, edge and length of the knife 23 should be adjustable, and different bodies 24 are used for timbers with different diameters. Instead of the shelling machine 20 a sufficiently stable and strong lathe can also be used if an appropriately long knife can be arranged and moved on it. The invention is not limited to the use of the machine 20 which looks like as a large pencil sharpener.

Reference is made now to Fig. 16 which shows a timber 1 roughly about the end phase of its use, wherein the conical shelling causes the timber 1 to take a conical shape where it has been tooled, and during shelling the timber 1 is pushed slowly in axial direction as the arrow shows in Fig. 16 and as a consequence of the shelling the length of the timber 1 gradually decreases. In Fig 16 with dashed lines the edge of the knife 23 has been shown, and the inclination angle a is indicated. The schematic knife 23 profile also illustrates that the edge should extend along the tangent line of the cone. It is also possible that the inner end of the knife 23 is arranged slightly above the axis 3 that can facilitate the rolling of the veneer.

A possibility of rotating the timber 1 is also illustrated in Fig. 16 when it has a cross like groove 39 at the rear face, and a pressing rod 40 is used that has cross-like ribs 41 at its front face that are fitted in the groove with matching profile, and the rotation of the rod 40 causes the timber 1 to rotate. Of course there can be several other ways of rotating the timber including the classical squeezing it in a rotating lathe-chuck

Instead of pushing the rod 40 into the shelling machine 20, it is also possible that during shelling, the body 24 of the machine is moved slowly towards the rod 40 along the previously described axial rails.

One aspect of the advantages of the conical shelling of the timber was the preferred pattern of the veneer by which luxury decoration elements can be made. There is a further advantage, namely the conventional manufacture of veneer requires large pieces of timber with a diameter well above e.g. 300 mm. However, there are trees which should be cut when the diameter of their trunk is smaller, i.e. in the range of about 70 to 250 mm. By using the method according to the invention with conical shelling, these narrower trees are well usable for preparing veneer which is much more valuable as if such trees were used only e.g. for making fire.